Does Ultrasound Guidance Axillary Incision Improve Sentinel Lymph Node Detection in Breast Cancer?

Overview

This single-center randomized controlled trial evaluates whether detecting the first lymph node at the axillary entrance with ultrasound guidance, followed by a targeted axillary incision over the pencil-marked projection, improves sentinel lymph node identification compared to the conventional axillary hairline landmark. The study hypothesizes that this technique enables a smaller incision, minimizes tissue dissection, and reduces operative time.

Axillary lymph node status is a key prognostic factor in breast cancer treatment planning. Accurate axillary staging is essential for optimal management. Sentinel lymph node biopsy (SLNB) provides reliable nodal assessment and is associated with lower morbidity relative to axillary dissection. The sentinel lymph node is the initial recipient of lymphatic drainage from the primary tumor, and breast lymphatics typically drain into at least one sentinel node. The majority of sentinel nodes are located in level I, particularly within the anterior axillary (pectoral) lymph nodes. These nodes are positioned at the inferolateral border of the pectoralis minor muscle, adjacent to the lateral thoracic vessels, and are typically in contact with the axillary tail of the breast. The standard axillary incision for SLNB is performed parallel to the Langer line, below the axillary hairline. Blue-stained lymph nodes are identified and excised by following the blue-stained lymphatic channels. The anterior axillary (pectoral) lymph node can be identified by placing the ultrasound transducer on the flattened lateral breast and axillary tail after appropriate patient positioning. Ultrasound guidance during an axillary incision at the projection of this lymph node allows direct access to the blue-stained sentinel lymph node. This approach reduces the extent of dissection and the need for channel tracking compared to the standard technique, resulting in a smaller incision, less tissue dissection, and shorter operative time. This study evaluates whether ultrasound-guided projection of the first lymph node at the axillary entry during an axillary incision, followed by tracing the blue-stained lymphatic channel and identifying adjacent lymph nodes, reduces operative time and morbidity by minimizing dissection compared to the standard axillary hairline landmark approach.